Bernita bought up an interesting subject on her An Innocent A-Blog today on chapter length in novels. Her point being that all the bickering that goes on over chapter length rules (so to speak) is silly and that chapters should be as long as they need to be. That's very true, and all the bickering can get silly at times, and we all know there is no such thing as a hard, fast rule in novel writing, but there are some things to take into consideration with chapter lengths that defy a simple 'as long as needed' explaination.
Chapters that are too long get tiresome to read. A good chapter gives a reader room to breathe. Reading 50 and 60 page chapters can feel like a marathon at times. Chapters should also provide a rhythm for the book. A feeling of ebb and tide as it were. With 50 page chapters you can't get in to much of a thythm when most novels today range from 250 to 300 pages. They should also have a beginning, a middle, and an end, just like the book itself. That gives each chapter a purpose. A really good chapter will also have a 'black moment' and even end in a 'cliffhanger' sort of feel, a reason to turn the page and go on to the next chapter. There are a lot of things to consider in chapter writing. It's a mini version of what there is to consider in novel writing as a whole--and it's just as exasperating.